This invention relates generally to a contact lens manufacturing facility for producing ophthalmic devices, and, in particular, to a SKU tracking and changeover method and apparatus for fabricating and packaging multiple stock keeping units (SKUs) of ophthalmic devices in a single manufacturing line.
The direct molding of hydrogel contact lenses is disclosed in U.S. Pat. No. 4,495,313 to Larsen, U.S. Pat. No. 4,680,336 to Larsen et al., U.S. Pat. No. 4,565,348 to Larsen, and U.S. Pat. No. 4,640,489 to Larsen et al., the entire disclosures of which are hereby incorporated by reference in this patent application. Essentially, these references disclose an automated contact lens production process wherein each lens is formed by sandwiching a reaction mixture between back curve (upper) and front curve (lower) lens curve assembly. The reaction mixture is polymerized, thus forming a lens, which is then removed from the front and back curves and further treated and packaged for consumer use.
The reaction mixture is sandwiched at a reaction mixture filling and lens curve assembly station wherein the polymerizable reaction mixture is first deposited into the front curve and the back curve is subsequently placed on top of the front curve to form a lens curve assembly. A carrier or pallet further transports the contact lens curve assemblies to other stations in the manufacturing line for further processing, until a completed polymerized contact lens is produced. The contact lens is then contained in a primary package along with a buffered solution. Typically multiple primary packages are housed in a carton, each carton having one or more labels which identify its contents.
One production line tracking and quality control system is disclosed in U.S. Pat. No. 5,555,504 to Lepper et al. That system provides bar codes on the lens carrying pallets which allow a control system to distinguish good and flawed lenses in the production line. That system, however, is not well suited for simultaneously handling multiple SKUs in a single production run in a single manufacturing line.
What is needed in the art and heretofore has not been available is a tracking and control system which ensures that separate SKUs can be simultaneously fabricated, packaged, and suitably labeled in a single production run in a single manufacturing line. The present invention satisfies this and other needs.
This invention provides a method for tracking multiple SKUs of ophthalmic devices in a manufacturing line, comprising the steps of:
assembling first molding devices at least one of said first molding devices having an identification means;
reading said identification means of said at least one of said first molding devices;
forming first molded parts using said first molding devices;
providing a plurality of carriers, said carriers having carrier indicators;
transferring said first molded parts to at least one of said plurality of carriers;
reading said carrier indicator of at least one of said plurality of carriers carrying said first molded parts; and
storing in machine-accessible memory the information associated with said identification means of said at least one of said first molding devices and the information associated with said carrier indicator carrying said first molded parts.
This invention further an system for tracking multiple SKUs of ophthalmic devices in a manufacturing line, the system comprising:
machine-accessible memory;
first molding devices at least one of said first molding devices comprising an identification means;
wherein said first molding devices make first molded parts;
means for reading said identification means of said at least one of said first molding devices;
a plurality of carriers, said carriers having carrier indicators;
means for transferring said first molded parts to at least one of said plurality of carriers;
means for reading said carrier indicator of said at least one of said plurality of carriers carrying said first molded parts; and
means for storing in said machine-accessible memory the information associated with said identification means of said at least one of said first molding devices and the information associated with said carrier indicator carrying said first molded parts.
This invention provides a method and apparatus for tracking molded parts in a manufacturing line. This invention makes it possible to use a single manufacturing line to make multiple stock keeping units (SKUs) in a single production run, that is, without having to shut down the line, or clear one SKU from the line before the production of a different SKU begins. There can be multiple SKUs at various locations in the manufacturing line simultaneously. This is particularly beneficial for making ophthalmic devices, in particular, contact lenses having various designs and powers, and lens curves which are used to form the contact lenses.
This invention further provides an automated method of tracking molding devices comprising putting an identification means on molding devices, and providing a database comprising fields for the status of said molding devices.
This invention further provides an automated method of scheduling the production of ophthalmic devices using molding devices for use in at least one manufacturing line which is capable of making multiple SKUs comprising:
a). communicating to a scheduling program demand for different ophthalmic devices;
b). communicating to said scheduling program the status of molding devices;
c). scheduling by said scheduling program based on the information communicated to said scheduling program in steps a and b which of said molding devices are to be used in said at least one manufacturing line.
This invention provides a method of scheduling the production of ophthalmic devices, preferably contact lenses, which consists of many stock keeping units (SKUs) which can be made in at least one manufacturing line. The molding devices, e.g., molds, mold halves, inserts and/or the cassettes can be interchanged among and within the one or more manufacturing lines to form the various SKUs. Preferably there are multiple manufacturing lines which share the molding devices, e.g., molds, mold halves, inserts and/or the cassettes, and a single scheduling program schedules the production of the different SKUs for the multiple manufacturing lines. This invention makes it possible to have fewer, inserts, cassettes, mold halves and/or molds for forming all the SKUs, than if each manufacturing line had a complete set of inserts, cassettes, mold halves and/or molds to make all the SKUs. Preferably the number of molding devices will be more than the number of manufacturing lines in which they are used, but preferably the number of molding devices will be limited so that not all of the manufacturing lines can make all of the same SKUs simultaneously. Further, this invention makes it possible to automatically schedule production based on product demand determined from historical data and/or actual orders, and the availability of molding devices to efficiently use the one or more manufacturing lines. This invention is particularly beneficial for making ophthalmic devices, in particular, contact lenses having various designs and powers.